DaVinci Resolve is heavily used in the film industry, where 24fps is the standard. Many of its features and workflows are fine-tuned for this frame rate. So I guess, at 30fps it might misinterpret the settings (like incorrectly assume the audio was recorded at a different sample rate (e.g., 44.1 kHz), causing the audio to play faster.
You can additionally check DaVinci Resolve settings if the timeline frame rate set to 30 fps, and the audio sample rate set to 48 kHz. And then try to re-import the audio.